Bulldozer



Aug. 22, 1933.

E. BACON BULLDOZER Filed- Feb. 23, 1932 s Shets-Sheet 2 me n w 0 E .12 dM r M M 2 Aug. 22, 1933.

E. R. BACON v BULILDOZER Filed Feb. 23, 1952 s Sheets-Sheet 3 INVENTORBY [dz/yard e 5050 Patented Aug. 22, 1933 I t a UNITEDVISTATESPATENT,OFFICE 1,923,412 BULLoozea Edward R. Bacon, San Francisco, Calif., as- Isignor to American Tractor Equipment 00., Oakland, Calif., a Corporationof Nevada ApplicationFcbruary 23, 1932. Serial No. 594,414 '2 Claims.(01. 37-444) l i This invention relates generally to devices comthesearms is also preferably tapered rearwardly, monly known as bulldozers,which are employed as by having the upper and lower walls 16 and 1'? toremove large amounts of earth, as in leveling convergent. or excavatingfor building construction. It has The rear ends of each of the arms 13are fulparticular application to bulldozers constructed crumed to somepart of the tractor capable of 60 as attachments for standard motortractors. applying considerablethrust, as for example the It is anobject of the present invention to devise side frame members 18. Thus asshown in Figapparatus of the above character in which the 5, a block 19is secured to each frame member scraper or other member engaging theearth can 18 at the side of the tractor, and this block be morepositively controlled. I In this conneccarries a journal stud 21.Journal block 22 is 65 tion the invention is characterized by the factfitted upon stud 21, and is in turn mounted upon that power can bepositively applied for lowering the rear end of the corresponding arm13. thescraper, as well as to raise the same. While various forms ofbowl assemblies can It is a further object of the invention to devise beutilized, the construction illustrated gives a bulldozer attachment forstandard tractors good results and consists of a scraper or bowl 70which will be relatively simple but sturdy in conmember 26 formed of acurved steel plate. The struction, which can be readily applied tostandlower edge portion 27 of plate 26 is adapted. to ard tractors,andinwhich certain operating parts dig into the formation being leveledor excawill be amply housed and protected. vated, while the upperportion of plate 26, which Further objects of the invention will appearis curved forwardly from the medial plate por- 76 from the followingdescription in which the pretion, servesto roll the earth forwardly asit is ferred embodiment of the invention has been set being displaced.Extending along the rear side forth in detail in conjunction with theaccomof plate 26, there is another plate 28, which can panying drawings.It is to be understood that be termed a torsion bowl. Plate 28 is bentto a the appended claims are to be accorded a range curvature greaterthan that of plate 26, and has 80 of equivalents consistent with thestate of the its upper and lower edge portions secured to prior art.plate 26, as by means of weld connections. Referring to the drawings:Plate 28 serves to impart rigidity and strength 1 is a Side onal view,illustrating a to the bowl assembly. Below plate 28, I provide 30tractor of the track laying type having attached another reinforcingmember 29, such as a struc-'-, thereto a bulldozer incorporating the pnt tural steel angle. The edges of angle 29 are like- V t o wisesuitably secured to the rear side of plate Fig.2is aperspective detailillustrating the con- 26, as by means of welding. Angle 29 extends struti n of the scraper bowl assembly, incorsubstantially the full length ofthe bowl assemported in my invention. bly, but plate 28 is somewhatshorter. Secured Fig. 3 is a cross sectional detail, taken along to the'ends of plate 26 and angle 29, as by means the line 3-3 of Fig. 1. ofweld connections, are the end plates 31.

Fig. 4 is a cross sectional detail taken along the To facilitate formingconnections with arms line 4-4 of Fig. 3. 13, the bowl assembly alsoincludes sockets or Fig. 5 is a cross sectional detail, showing theshoulder members 32, which are preferably holmanner of mounting andfulcruming the thrust low, and which can be formed of steel castings orarms to the frame of the tractor. of steel plates welded together.Sockets 32 are That form of the invention illustrated in the formed tofit upon the rear faces ofplate26 and drawings consists of a structure10, shown apangle 29, and are rigidly secured thereto and to plied to atractor 11 of the track laying type. the ends of plate 28, as by meansof weld con- Structure 10 includes in general a scraper bowl necticns.Flanges 33 formed on sockets 32 assembly 12, and thrust or pusher arms13 confacilitate bolting or riveting the bowl assembly nected to the endportions of the scraper bowl to the flanges 34 formed upon the forwardends assembly and extending rearwardly along the of arms 13.

sides of the tractor 11. Each of the thrust arms The positioning of thestructure described 105 13 is preferably hollow or of skeletonizedconabove, is controlled by an actuating mechanism struction, being shownformed of side walls 14, 36, together with. motion applying mechanismandupper and lower walls 16 and 1'7. A conhaving points of connectionwith the actuating venient mode of manufacture is to form these means,the structure 10 and the tractor. As

arms of steel plates welded together. Each of shown in Fig. 4-, theactuating means 36 is preferably the hydraulic type, consisting of acylinder 37 within which a double acting sliding piston 5 inder 37. Theactuator is disposed within one,

of the arms 13, and is secured thereto by means of a pivotal connection39, between the side walls of the arm and the cylinder 37. Hydraulicconnections to *the ends of the cylinder 37 are made through flexiblepipes 41, which extend through the upper wall 16 of the arm and whichare connected with a hydraulic system provided upon the tractor. Byapplying hydraulic pressure to one of the flexible pipes 41, whileexhausting the other, rod 38 can be positively forced in eitherdirection.

, Mounted upon the bowlof the assembly 12, by

means of journal blocks 42, there is a rotatablehorizontal shaft 43.Fixed to one end of shaft 43, and arranged within one of the sockets 32,there is a lever arm 44. Pivotal connection 46 serves to connect the endof this lever arm, with the forward end of rod 38 of the actuatingmeans. Likewise fixed upon shaft 43, and arranged in spaced relationshipbetween the sockets 32, are the lever arms 47. .Rigid links 48 serve topivotally connect the ends of lever arms 47, with brackets 49 mountedupon the sides of the main frame 51 of the tractor.

Operation of my device is believed apparent from the above description.Upon operating the hydraulic actuator 36, shaft 43 is turned a certainamount, andthe scraper bowl assembly is then positioned accordingly.There will be no tendency for the scraper bowl assembly to ride upon theformation being leveled or excavated, because the motion applying meansby which the position of the bowl assembly is determined is relativelyrigid. Furthermore, by control of the actuator, the bowl assembly can bepositively forced downwardly under power, instead of merely relying uponthe weight of the bowl assembly'and associated parts. The structureformed by the bowl assembly and the side arms 13 is relatively rigid andis capable of withstanding severe stresses without breakage or permanentdeformation. Likewise the mounting of the actuator, and certain othermoving parts,

within one of the hollow arms 13, adequately protects these partsagainst breakage, and prevents contact with masses of earth beingleveled or excavated.

I claim:

1. In a.bulldozer attachment for tractors, a structureincluding ascraper adapted to be positioned in front of the tractor, and a pair ofthrust arms secured to the end portions of the scraper and extendingrearwardly along the sides of the tractor, said arms being adapted to befulcrumed upon the tractor, actuating means mounted upon said structureand housed within one of said arms, and motion transmitting means havingpoints .of connection with the actuating means, said structure, and thetractor, said last means-"including links and levers whereby saidactuating means oan exert a positive force between the tractor and saidstructure to urge said structure downwardly.

2. In a bulldozer attachment for'tractors, a

structure including a scraper adapted to be positioned in front of thetractor, and a pair of:

thrust arms secured to the end portions of the scraper and extendingrearwardly along the sides of the tractor, said arms being adapted to befulcrumed upon the tractor, actuating means mounted upon said structureand housed within one of said arms, a horizontal shaft journaled to saidstructure and arranged adjacent the forward end of the same, rigidmotion transmitting means connecting said shaft with said actuatingmeans, and rigid motion transmitting means connecting said shaft withthe forward portion of the tractor, whereby said actuating means canapply positive forces, to said structure to raise or lower the same. I

3. ma bulldozer attachment-for tractors, a structure including a scraperadapted to be positioned in front of the tractor and a pair of thrustarms secured to the end portions of the. scraper andextending rearwardlyalong the sides of the tractor, said arms being adapted to be fulcrumedupon the tractor, actuating means mounted upon one of said arms, ahorizontal shaft journaled to said structure adiacent the forward end ofthe same, a lever fixed to said shaft, a rigid rod connecting said leverwith said actuating means, another lever flxed to said shaft, and arigid link connecting said last named lever with the forward portion ofthe tractor.

-4. In a bulldozer attachment 'for tractors, a structure. including ascraper adapted to be positioned in front of the tractor and a pair ofthrust arms secured to the end portions of the scraper and extendingrearwardly along ,the sides of the tractor, said arms having their rearend portions adapted to be fulcrumed upon the tractor, actuating meansmounted upon one of said arms, a horizontal shaft journaled to saidstructure adjacent the forward end of the same, a lever fixed to saidshaft, a rigid motion transmitting rod con,- necting'said lever withsaid actuating means, a pair of additional levers fixed to said shaftand arranged in spaced relationship between said arms, and a pair ofrigid links serving to connect, said last mentioned levers withtheforward portion of the tractor.

5. In a bulldozer attachment for tractors, a structure including ascraper adapted to be'positioned in front of the tractor and a pair ofhollow thrust arms secured to the end portions of the scraper andextending rearwardly along the sides of the tractor, the rear endportions of said arms being adapted to be fulcrumed upon the tractor,

hydraulic actuating means mounted within one {23 of said arms, saidactuating means including a cylinder, a pistonslidably fitted within thecylinder, anda piston rod secured to the piston and extending from oneend of the cylinder, means for pivotally mounting said cylinder to saidone arm,

and motion transmitting means having points of connection with theactuating means, said struc ture and the tractor, whereby said structurecan be raised or lowered upon operation of said actuating means.

6. In a bulldozer attachment for tractors, a

structure including a scraper adapted to be positioned in front of thetractor and a pair of hollow thrust arms secured to the end portions ofthe scraper and adapted to extend rearwardly along 4 der, a pistonslidably fitted within the cylinder,

and a piston rod secured to the piston and extending from one end of thecylinder, means for pivotally mounting said cylinder to said one arm, a

horizontal shaft journaled to said structure adiacent the forward end ofthe same, a lever fixed tions of the assembly and extendingrearwardlyalong the sides of the tractor, said assembly including acurved scraper plate, a curved plate forming a torsion bowl secured uponthe rear side of the scraper plate and sockets secured to the endportions of the torsion bowl member and serving as a means for mountingthe assembly upon the forward ends of said arms, and means for raisingand lowering said structure with respect to the tractor.

EDWARD R. BACON.

